There are two Cannes Film Festivals, really. One involves all the good, enriching work of waiting in line to see the best of world cinema. The other is all about beach parties and gala soirees, all “who’s here” neck-craning and gown envy. The apex of that second Cannes, the glitz and champagne gulping, is the annual amfAR gala, a fund-raiser for AIDS research held at the ludicrously picturesque Hôtel du Cap-Eden-Roc in nearby Antibes. With its starry guest list and sublime setting, amfAR has long been the event of the Cannes social schedule, the hardest-to-get invite of the whole festival. So, I decided to go!

Well, O.K., I begged to go, using photographer Mark Seliger’sVanity Fair Instagram portrait studio as my in. Somehow it worked, and yesterday evening I found myself skittering down the red carpet, trying to wait patiently as a model in front of me had her picture taken by dozens of shouting photographers. Eventually some handsome young man, who I’m assuming was her publicist, told me, “It’s much easier if you just walk through,” so I did, Adrien Brody striding down the carpet behind me. I climbed the steps to the hotel, or one building on the hotel’s sprawling grounds, and then staggered out onto the lawn, where a long gray carpet was laid out, leading down a slope to the sea. At the bottom of the hill was a Jeff Koons sculpture that would later be auctioned off for millions of dollars.

The crowd was intimidating. The amfAR gala includes a fashion show, so the pre-dinner cocktail reception was lousy with models, impossibly tall, long-limbed creatures in beautiful couture. These beings, and their handsome dates, were certainly not the same species as me—I was surrounded by gorgeous aliens. So I beat a hasty retreat to the side, where I struck up a conversation with an older gentlemen of indeterminate European origin. “What brings you here?” I asked. He smiled strangely at me and said, “I don’t know.” Turns out he runs the Monaco International Film Festival and has been going to amfAR for years, so his not knowing why he was there was more of an existential question. He explained to me that he lived in a palace (his word, “palace”) in Morocco, because he did not have to pay taxes there. “I’m an artist, baby,” he said, before telling me about living in downtown New York City in the 1970s and hanging out with the Ramones.

We were interrupted by dreadlocked socialite-model Morgan O’Connor, he and his date sidelining themselves because they felt awkward smoking on the pristine gray carpet. “I feel like I’m ashing everywhere!,” O’Connor’s date said sheepishly. They introduced themselves to my new European friend, let’s call him Prince Albert, and they swapped stories about O’Connor’s native Palm Beach. (Albert to Morgan: “I got drunk at that bar with Bobby Kennedy!”) When Prince Albert had to excuse himself to take a phone call (from the ghost of amfAR co-founder Elizabeth Taylor, I imagined) O’Connor surveyed the scene and said, “I feel like this party has the most psychos of any party.”

It began to drizzle, so everyone headed off to the massive tent where dinner was being held. The press table where I was seated was, predictably and understandably, all the way in the back. But that gave me a good view of the scene. I did a lap around the room with a colleague from New York magazine who was also sitting at my table, me trying to be invisible while she said hi to various models she knows. (Everyone at Cannes parties is more fabulous than you.) I watched as Michael Fassbender apologized for stepping on the train of Chanel Iman’s gorgeous white gown. Scenesters like the ubiquitous Brant brothers, Peter and Harry, swanned around the room, mingling with various willowy women.

Back at our table, a blond woman wearing chainmail gloves sat down next to my colleague, clearly having enjoyed a glass or six of the free-flowing Moët champagne at the cocktail party. She introduced herself as a producer, which was odd, because everyone at this table was supposed to be press. As the night progressed, we began to suspect that this woman was perhaps not supposed to be there. As we sat waiting for the event to begin, models walked by complaining about being cold—this was the only air-conditioned room I’ve been in at Cannes. Then model Karlie Kloss, bestie of Taylor Swift, and a few of her model friends took the stage to kick off the evening, introducing singer Charli XCX, who sang a couple of her hits. So if nothing else, I now finally know who Charli XCX is.

Harvey Keitel, whose Youth was a festival hit this year, then came out to introduce the first auction item, a huge package including tickets to the Golden Globes, the Oscars, assorted post-awards parties, and a private photo session with Bradley Cooper (who was presumably doing a kind favor for Harvey Weinstein, whose Weinstein Company is a leading amfAR sponsor). “You will be alone with him, no assistants! He will take your picture!” said ebullient auctioneer Simon de Pury, trying to get the bidding going. The item opened at €100,000. It went for €220,000, after three bids.

Next up were Robin Thicke and Rita Ora—”Hello, I’m Rita,” Rita Ora said—introducing a Gallic wine tour package, Thicke helpfully pronouncing all the French words Ora couldn’t. It went for €70,000. Then a Picasso painting went for €700,000.

The drunken interloper at our table had remained mostly silent up to this point, speaking up only to ask if we minded if she smoked. (It’s France! Smoke ’em if you got ’em!). But then famed Italian tenor Andrea Bocelli came out to sing “Con te Partiro,” and our tablemate went absolutely nuts. She screamed when he walked out, immediately jumping out of her chair and clapping and whistling. Throughout the song she made pained whimpers and moans, clutching her chest and weeping. The rest of the audience was also very receptive—two private dinners with Bocelli were auctioned off, going for a combined total of €2,000,000. Only at Cannes is Andrea Bocelli a bigger draw than Bradley Cooper.

After that display of emotion, Michelle Rodriguez and Adrien Brody kicked off the sale of a designer motorcycle, which went for €300,000. The crowd was losing its focus, milling about and talking loudly until an announcer asked for quiet. At one point I saw actor Ethan Suplee walk by, looking as confused as I was to find him there.

Then it was time for the fashion show, an assemblage of designer looks curated by famed former Vogue Paris editor Carine Roitfeld. The models walked beautifully, navigating tricky stairs in vertiginous heels, while D.J. Mark Ronson played some pop hits, including his own “Uptown Funk.” Afterwards, the whole collection was auctioned off for €800,000, Karlie Kloss adamantly trying to get the number up by offering dinner with a model of the bidder’s choosing. “Dinner with me is worth at least 25,000,” she said at one point. Alas it was to no avail; the bid never rose above €800,000.

During a lull in the auctioning, I went outside to check out the scene beyond the tent. Harvey Weinstein was there, holding court. Jake Gyllenhaal, Weinstein’s great Oscar hope this year, came out to chat with him for a bit, before hopping on the back of a golf cart and disappearing into the night. Speaking of disappearing, when I got back to my table, the mysterious woman in metal gloves was gone, maybe off making a sacrifice to Andrea Bocelli. She would return, though.

I spotted Diane Kruger striding by in a wonderful feather tutu sort of a dress. Between that outfit and her festival film Maryland, Kruger is having a great Cannes. Robin Thicke also wandered past, clutching his date’s hand as she stared blankly.

The room got lively as Mary J. Blige came out to perform a song. “[Tonight] is about saving lives, and that’s what I’m about,” she said. Blige has indeed saved many lives, I suspect.

Marion Cotillard and Michael Fassbender then introduced a Banksy piece up for auction, one from Leonardo DiCaprio’s personal collection. Fassbender called out DiCaprio, whom every reporter had been searching for all night, asking him to stand up, but I couldn’t see if he did from my place in the back of the room. DiCaprio would sadly elude me all evening. The Banksy sold for €1,000,000. Cotillard then said, “I spoke to Leo earlier and he has agreed to add a special experience to this occasion.” The special experience was a seat at DiCaprio’s table at an upcoming environmental fund-raiser, followed by dinner on a yacht in St. Tropez. “Money can’t buy experience,” de Pury said while auctioning the item. Which is true, except for here. Money absolutely can and does buy experience in Cannes. The item sold for €220,000.

At this point the drunken goddess at our table had returned, only to promptly fall asleep in her chair.

Then it was time for the big Jeff Koons presentation, “Eye of the Tiger” blaring incongruously while a video detailed how much money Koons works usually go for. The sculpture at auction at amfAR was “Coloring Book,” from Koons’s “Celebration” series. The bidding started at €1,000,000 and ended at €12,000,000.

Eva Longoria then bought an Andy Warhol portrait of Elizabeth Taylor for €550,000.

One of my favorite parts of the evening: Frances McDormand strode out on stage and said, “I’m here to offer you something we haven’t seen tonight: a little piece of subtlety.” Sick burn, McDormand! She introduced a work by Alexander Calder, which sold high.

During a break I went to the men’s room and almost bumped into Robin Thicke, who was making conversation with other bathroom-goers. “Marrakech will be ours!” he said to one guy, in reference to something I would probably not understand even if it was explained to me.

As I returned to my table, John C. Reilly, seemingly everywhere at Cannes this year, was introducing a sculpture that went on to sell for €2,000,000.

The drunk producer sitting next to us woke up and re-introduced herself to us. I gave her my e-mail address so she could pitch me her projects. Probably a mistake, but it at least stopped her from pitching me right there at the table.

Actress Alicia Vikander took the stage, jokingly saying of her absent co-presenter, Jake Gyllenhaal, “my companion had too many drinks.” (Same story at table 77, Alicia.) She introduced a fabulous vacation at a resort in the Maldives (“Please, we all need a little vacation after a week in Cannes”). At one point the auctioneer indicated that Leonardo DiCaprio made a €60,000 bid, and yet again we all craned our necks to spot him, but I could not find him. He’s truly Gatsby-esque!

Then out walked Karlie Kloss again, this time with Kendall Jenner and Gigi Hadid. Kloss once again tried her hand at hyping the crowd, encouraging bids for a photo session with Mario Testino. She or one of the other models, I couldn’t tell who, said, “Wait ’til you see his assistants.” Another added, “They’re fun to look at.” Kloss kept talking over the auctioneer, saying that she and her fellow models have a combined total of 40,000,000 Instagram followers, and that they would Instagram the Testino photo of whoever bid the highest. The bid, which held firm at €350,000, went to an unnamed woman from Peru.

After the auction wound down, Imagine Dragons came out to play a few songs. To my pleasant surprise, they were great—loud and spirited and graciously promoting the cause in between songs.

And then the evening reached its peak: a drunk woman made her way onto the stage and started saying things into a microphone. It took me a second to realize that it was our drunk woman, from our table! She made it! She got on the stage at amfAR. She urged the crowd to clap, or something, and was then gently escorted off. It was the last we’d see of her—that night, anyway. I feel confident that I’ll see her again someday, if only in my dreams.

Then it was time for the after-party, on the same deck where Vanity Fair holds its bi-annual Cannes party. It was crowded and we didn’t have V.I.P. access (we had gray bracelets; we needed black ones), so we didn’t stay long. But we were there long enough to spot Jake Gyllenhaal, returned from wherever he went on that golf cart, and his fellow festival jury member Sienna Miller, standing at the bar with some enticing-looking drink. My colleague asked her what it was and she kindly said to the bartender, “Make her one of these.” Thanks, Sienna!

Supposedly Leonardo DiCaprio was up on a private deck with four bodyguards. Another reporter pointed at the deck and I squinted to find DiCaprio in the dark. But it was no use. Mine eyes were not meant to gaze upon Leo that night.

Mark Ronson was back D.J.-ing, so, loosened by too many glasses of champagne, we danced. John C. Reilly, who could have been in the V.I.P. area, cut a rug with the commoners.

And then it was time to go home, to contend with hangovers and early-morning screenings. After all that, it was back to the other Cannes.